Figure 3.

Example SEM and NanoSIMS images of one 10 × 10 μm area of DOM 08006. (a) SEM secondary electron image; (b) NanoSIMS ¹⁶O ion image; (c) NanoSIMS ¹²C image, (d) SEM secondary electron image of ¹³C- and ¹⁵N-rich organic nanoglobule, area marked by box in (a,f,g); (e) NanoSIMS δ¹⁷O/¹⁶O image with a ¹⁷O-rich presolar silicate (DOM-79, Table 2) indicated; (f) NanoSIMS δ¹²C/¹³C image with a ¹³C-rich presolar SiC indicated; and (g) NanoSIMS δ¹⁵N/¹⁴N image with two clear “hotspots” of enhanced ¹⁵N abundance, one of which corresponds to the nanoglobule in panel (d). Unless otherwise noted, scale bars are 1 μm. Delta values are deviations from a standard ratio in permil, defined as: δR=(R_measured/R_standard − 1) ×10³